The present invention relates to an ester-containing lubricating composition and processes therefor and therewith, such as use in downhole drilling operations.
The art of boring into the earth with a drill string, particularly for oil and gas production, typically involves rotating a toolhead bit fastened to the end of a string of drill pipe with the string being driven by a surface engine. A fluid called a “drilling mud” is injected into the hole at the point of the bit by circulating the drilling mud down the inner space of the string through openings in the bit and up through the annular space of the well. The main purposes of the drilling mud are to clean the bit, take up debris from the well, and stabilize the formation walls in contact with the drilling mud. An additional important aspect of the drilling mud is to lubricate the drill bit to prevent drill-pipe sticking for which various types of lubricating agents have been incorporated into the drilling mud. There is a significant and continuing need for a lubricating composition that has good handling characteristics, can be readily mixed with new or existing drilling fluids, has a relatively low cost and toxicity, and helps improve the lubricity of the drilling fluid or similar fluid that is mixed with or contains such lubricating composition. In addition, a lubricating composition that comprises components that can be obtained from by-products of manufacturing processes that provide a use for such by-products other than disposal would also be a significant contribution to the art and to the economy.